• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.348-354
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• 1987

The behavior of crab, Charybdis japonica h. Milne EDWARDS, to the net pots with baits was investigated alternately in the experimental tanks. One of the pots being dropped on the tank bottom, the crabs touched it to obtain the bait probably reacted by their senses of smell and sight, and increased gradually in the number of touch to show a maximum within 30 min. The crabs, if touched circular pots, were guided more easily to the pot entrances than the case of touching square ones, but the guidance from the vicinity of the entrances into the pots was easier in the square. When the crabs entered the pots, they always showed a sharp precaution. However, most of enterings were made mainly within 30 minutes and easier in pots with lower entrances. If 30 min. elapsed, the entering was little made by the decrease in the number of touch and the getting-out was remarkable, especially in pots with low entrances. But, in all the pots the getting-out was hampered by the drawing of the entrance tips into the pots. In case in which flappers were attached to the entrance tips, the entering was very hampered, hut the getting-out was not shown.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.3
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• pp.257-265
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• 1996

The combined hydroacoustic and bottom trawl surveys were conducted in the Cheju southeastern area by the training ship "KAYA" belong to Pukyong National University in July 1995 and the traning ship "NAGASAKI MARl]" belong to Nagasaki University in April 1994, respectively. The main purpose of the investigations was to provide the basic data for the management and the biomass estimation of commercially important demersal fish stocks in this area. Fish samples were collected by bottom trawling from 10 trawl stations randomly selected in the survey area, and the species and length compositions of trawl catches were examined. The fish school target strength for demersal fish aggregations was related to the catchability of trawl net with a 90 mm mesh codend. The most abundant species in the 1995 trawl stations were Japanese flying squid, sword tip squid and red horsehead and that of the 1994 trawl stations Japanese flying squid and blackmouth goosefish. The average weight per cubic meter of trawl catches collected by bottom trawling in the Cheju southeastern area were $1.0791{\times}lO^-4$kg/$m^3$ in the 1994 survey area and $1.3636{\times}lO^-4$kg/$m^3$ in the 1995 survey area, respectively. The catch data by cover net suggest that the efficiency of trawl net could affect the weight normalized target strength values for demersal fish aggregations. That is, the average target strength per unit of weight dropped from - 33.1 dB/kg using the total catch by codend and cover net to - 30.5 dB/kg using only the catch data by codend, and a change of2.6 dB/kg was observed.ange of2.6 dB/kg was observed.

• Journal of the Korean Society for Library and Information Science
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• v.40 no.4
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• pp.267-286
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• 2006

Tools are needed to have access to more effective information and to select it in the environment of digital information where information pours in. and some of the advanced techniques to make up these tools are metadata and annotation. Annotation additionally records the marks for the supplementary explanation of and emphasis on a specific part of the original text and kas more various merits than metadata in terms of the search and use of digital resources. This research aims at suggesting methods that annotation. which has a range of functions including access to information. its reuse and sharing in the digital surroundings of late, can be applied to digital contents such as web services, digital libraries and electronic books. As to the research method, the case studies of annotation systems applied to web services and digital libraries have been carried out, and the metadata formation of the systems has been analyzed.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.313-324
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• 2023

Species composition and seasonal variation of aquatic organism were collected by pot and trammel net in the coastal waters of Taean in 2018. A total of 4,501 individuals belonging to 78 species were collected in two type of gears. The dominant species in the study area was Strongylocentrotus nudus (Echinodermata). In the pot survey, crustaceans were the most common taxa, with 52 species including Palaemon gravieri, whereas fish were dominant in trammel net with 57 species including Okamejei kenojei. Clustering analysis revealed two distinct groups, indicating that the composition of aquatic organism varies according to oceanographic condition and environmental changes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.1
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• pp.36-42
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• 2002

This study was conducted to estimate the number of lost or abandoned plastic sea-eel pots and investigate the actual condition on the ghost fishing happened from the pots during the period of August 1996 and January 2002 In the Southern Sea of Korea. The average number of lost or abandoned sea-eel pots in the investigated sea area were 34 ea/$\textrm{km}^2$ and was the lowest as 5 ea/$\textrm{km}^2$ Sea Area code # 113 and was the highest as 94 ea/$\textrm{km}^2$ in the Sea Area code #106. Pots number in accordance with water depth was the highest as 89 ea/$\textrm{km}^2$ on the level of 61 ~70m and there was no collection for the sea-eel pot over 130m water depth. The average catch rate of ghost fishing happened from the lost or abandoned pots was 8.1% and the highest rate was 25% in the Sea Area code #224 and there were no catches in the Sea Area code # 92, 110, 243 and 253. The number of lost or abandoned sea-eel pots continued ghost fishing were estimated as 14.2 ea/$\textrm{km}^2$ in the Sea Area code # 99 and was the highest. Catch rate of ghost fishing according to water depth was the highest as 23.5% on the level of 71~80 m, and the number of lost or abandoned sea-eel pots continued ghost fishing were estimated as 12.7 ea/$\textrm{km}^2$ on the level of 81~90m and was the highest. Length distribution of sea-eel which were caught from ghost fishing was 25.5~66.0$\textrm{cm}^2$

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.63-73
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• 1995

A remote telesounder system was manufactured to investigate the behavior and distribution characteristics of fish and was tested to verify its performance and effects int he set net fishing ground located off the Namhae island, Oct. 26~27, 1994. The activity pattern of fish was observed at the buoy station installed in a set net and it was also analyzed simultaneously at the remote base station on land located at distance of about 1.5km away from the buoy station. Several findings at both the buoy station and the base station were as follows: The images of color display monitor at the base station on land were very well coincident with the records observed at the buoy station. The lower part of slope net and bagnet fluctuated irregularly, and its variations were about 3.6m and 6.0m, respectively. In the daytime, the fish school entered playground, passed slope net with 5~7m depth, moved dispersedly at night and at twilight the entrance was rare. In the bagnet, in the daytime the fish school swam in the layer of 8m in depth, at night the fishes dispersed in the entire layer and at twilight they formed dense school. The fishes caught by the set net were about 500kg with 20 species. Anchovy was the most dominant species. In conclusion, the remote telesounder was a convenient and powerful system for investigating the distribution pattern and the swimming behavior of fish entering in set net.

• Horticultural Science & Technology
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• v.18 no.1
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• pp.33-38
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• 2000

This study was conducted in an effort to meet the need for domestic production of hydroponic media and for medium development using recycled hydroponic rockwool slabs. Two experiments were conducted to evaluate the growth of plug seedlings of petunia 'Romeo' in various mixtures including particles of used rockwool slabs (rockwool particles) and wood chips. In the first experiment, seedlings were grown in plugs filled with mixtures of steam- sterilized rockwool particles and chestnut wood chips, which had been weathered for six months and screened through either 2.8 mm or 5.6 mm sieve, at the mixing ratio of 100:0, 75:25, 50:50, 25:75, or 0:100 (v/v). In the second experiment, seedlings were grown in plugs filled with twenty different mixtures of steam-sterilized particles of used hydroponic rockwool slabs with 4 mm chestnut or pine wood chips, coir, peatmoss, or perlite. In the first experiment seedling growth was not affected by particle size of chestnut wood chips, was superior in the control (commercial plug medium) and in 100% rockwool particles, but was suppressed as mixing ratio of chestnut wood chips increased. In the second experiment, leaf length, and shoot fresh and dry weights were the greatest in rockwool particles+peatmoss+coir treatment, followed by rockwool particles+peatmoss treatment. Leaf length was suppressed as ratio of wood chips increased, especially of chestnut wood chips. Root development was the greatest in rockwool particles+peatmoss+perlite treatment, followed by the control, and rockwool particles+peatmoss+coir treatment. The growth was suppressed as the mixing ratio of rockwool particles, peatmoss, or coir decreased.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.543-549
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• 1997

The problems in the existing modeling rules for fishing nets, especially in the Tauti's rule which had been used most commonly, were investigated and it was found that the rules could not give a good similarity between the prototype and model nets because they din neither analyze the flow resistance of nets accurately nor decide the ratio of flow velocity between the two nets properly. Thus, the modeling rule was newly derived by regarding the nets as holey structures sucking water into their mouth and then filtering water through their meshes as in the previous paper. The similarity conditions obtained, between the two nets distinguished by subscript 1 and 2, are as follows; $$\frac{d_2}{d_1}=\sqrt{\frac{l_2}{l_1}},\;\frac{N_2}{N_1}=(\frac{d_1}{d_2})^{1.5}\frac{L_2}{L_1},\;\varphi_1=\varphi_2,\;\frac{d_{r2}}{d_{r1}}=\sqrt{\frac{L_2{(\rho_{r1}-\rho_{w1})}}{{L_1{(\rho_{r2}-\rho_{w2})}}$$ $$\frac{N_{a2}}{N_{a1}}=\frac{W_{a1}}{W_{a2}}(\frac{L_2}{L_1})^2,\;\nu_1=\nu_2\;and\;\frac{R_2}{R_1}=(\frac{L_2}{L_1})^2$$, where L is the length of nettings, d the diameter of netting twines, 2l the mesh size, $2\varphi$ the angle between two adjacent bars, N the number of meshes at the sides of nettings, $d_r$, the diameter of ropes, $\rho_r$, the specific gravity of ropes, $W_a$ the weight in water of one piece of float or sinker, $N_a$ the number of floats or sinkers, $\nu$ the flow velocity, and R the flow resistance of net. In the case where the model experiments aim at investigating the influence of weight in water of nettings on their shapes in nets subjected to the water flow of very low velocity, however, the following condition is added; $$\frac{\rho_2-\rho_{w2}}{\rho_1-\rho_{w1}}=\frac{d_1}{d_2}$$ where $\rho$ is the specific gravity of netting twines.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.1-11
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• 2020

Noksan is a green area in the form of a hill located inside Gyeongbokgung Palace, unrecognized as a cultural heritage space. This study analyzed the literature and the actual site to derive its landscape meaning by examining the background for the formation of Noksan and how it changed. As a result, the identity of Noksan was related to the geomagnetic vein, pine forest, and deers, and the following are its landscape meaning. First, several ancient maps, including the 「Map of Gyeongbokgung Palace」 depicted the mountain range continuing from Baegaksan(Bugaksan) Mountain to areas inside Gyeongbokgung Palace, and Noksan is a forest located on the geomantic vein, which continues to Gangnyeongjeon Hall and Munsojeon Hall. On Bukgwoldo(Map of Gyeongbokgung Palace), Noksan is depicted with Yugujeong Pavilion, Namyeogo Storage, office for the manager of Noksan, the brook on north and south, and the wall. It can be understood as a prototypical landscape composed of minimal facilities and the forest. Second, the northern palace walls of Gyeongbokgung Palace were constructed in King Sejong's reign. The area behind Yeonjo(king's resting place) up to Sinmumun Gate(north gate of the palace) was regarded as the rear garden when Gyeongbokgung Palace was constructed. However, a new rear garden was built outside the Sinmumun Gate when the palace was rebuilt. Only Noksan maintained the geomantic vein under the circumstance. However, the geographical features changed enormously during the Japanese colonial era when they constructed a huge official residence in the rear garden outside the Sinmumun Gate and the residence of the governor-general and road in the site of the Blue House. Moreover, Noksan was severed from the foothill of Baegaksan Mountain when 'Cheongwadae-ro(road)' was constructed between the Blue House and Noksan in 1967. Third, the significant characteristics and conditions of the forest, which became the origin of Noksan, were identified based on the fact that the geomatic state of the northeastern side of Gyeongbokgung Palace, the naecheongnyong area in geomantic terms(the innermost 'dragon vein' among the veins that stretched out from the central mountain toward the left side), and they planted pine trees to reinforce the 'ground vein' and the fact that it was expressed as the 'Pine Field' before the Japanese Invasion of Korea in 1592. The pine forest, mixed with oaks, cherries, elms, and chestnuts, identified through the excavation investigation, can be understood as the original vegetation landscape. Noksan's topography changed; a brook disappeared due to mounding, and foreign species such as acacia and ornamental juniper were planted. Currently, pine trees' ratio decreased while the forest is composed of oaks, mixed deciduous trees, some ailanthus, and willow. Fourth, the fact the name, 'Noksan,' came from the deer, which symbolized spirit, longevity, eternal life, and royal authority, was confirmed through an article of The Korea Daily News titled 'One of the seven deers in Nokwon(deer garden) in Gyeongbokgung Palace starved to death.'

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.2
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• pp.129-139
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• 2002

Fish distribution characteristics are essential to assess and estimate fisheries resources in a particular area. The primary goal of this study is to determine the distribution characteristics by the bottom trawling in the Yellow Sea west of South Korea. The surveys were carried out between 33$^{\circ}$00'N~37$^{\circ}$00'N latitude and 124$^{\circ}$00'E~126$^{\circ}$00'E longitude at EEZ(Exclusive Economic Zone) of Korea in Yellow Sea on May and August, 1999 and April, 2000. The ships used in this survey were the R/V Chung-kyeong(G/T 300) and R/V Dong-baek(G/T 1,050) of Yeosu National University. The results obtained can be summarized as follows 1. From the trawl data the fisheries resources are seriously decreasing through most of the species(about more 50%) have been appeared only one time at the bottom trawl on April, 2000. The total fish species caught by the trawl net during the 3 times survey were 106 species and a few species(dominant species) of these occupied 50~90% of the quantity of the total quantity by number or by weight. Among the dominant species the tanaka's snailfish was recorded to be the most dominant species in the survey area. The fish species in the Yellow Sea were clustered according to the regions. They clustered in two or three partes to the south-north direction in the spring season and clustered in two parts to the on-off shore direction of the shore in the summer season. Most of the fish caught at the the trawl net with cover-net(30.3mm) were small sized. They were shorter than 15 cm in length and the extruding rate of the cod-end which was 60mm mesh size ranges about 90%. 2. The densities of the number and weight per unit volume derived from the total catches sampled in April, 2000 survey were $1532.2{\times}10^{-6}fish/m^3$ and $39.55{\times}10^{-6}kg/m^3$, respectively. 3. The density variation of fish population between 1999 and 2000 showed a slight tendency to increase.